> On Nov 21, 2018, at 6:25 PM, Scott Kitterman <post...@kitterman.com> wrote:
>
>>> Where is the ".localdomain" coming from?
>>
>> It might be read from a file, or it might be set at compile time? The
>> person packaging Postfix for Debian should know. In any case, the Wiki
>> article https://wiki.debian.org/Postfix states that you should set the
>> 'myhostname' and 'mydomain' parameters explicitly.
>
> This is Debian specific:
>
> +# Debian GNU/Linux specific: Specifying a file name will cause the
> +# first line of that file to be used as the name. The Debian default
> +# is /etc/mailname.
> +# +#myorigin = /etc/mailname
>
> It's been that way for at least 18 years (well before I was involved in
> maintaining Postfix in Debian).
That said, absent any domain part in the system hostname and with
no explicit setting of mydomain in main.cf, the default, compiled-in
value of mydomain is "localdomain". This is typically not what
"postconf -d" reports, since the latter reports the default name
derived from the system hostname. But it can be teased out with
an unqualified "myhostname" override:
$ mkdir temp
$ echo "myhostname = foo" > temp/main.cf
$ touch temp/master.cf
$ postconf -c $PWD/temp mydomain
mydomain = localdomain
--
Viktor.
